This invention relates to head-set assemblies and more particularly to microphone booms used in head-set assemblies.
As is known in the art a head-set assembly generally includes a microphone assembly disposed at the first end of a microphone boom such that the microphone may be disposed near a user""s mouth. A second end of the boom is connected to either a so-called hanger or to a receiver which is adapted to rest on a portion of the user""s head such as an ear for example. Thus, the boom physically connects and the microphone to the receiver.
One type of microphone boom is generally provided from a hollow tube having a body made of metal or other suitably stiff material. One or more wires from the microphone may then be disposed through the hollow center of the tube to electrically connect the microphone to a transmit path amplifier. Such microphone booms however, are generally stiff, cumbersome, and relatively heavy when worn on a user""s head for a long period of time.
Moreover, it is relatively difficult to adjust and maintain the position of the microphone when the headset is worn by different users. To solve these problems, the microphone can be coupled to a flexible microphone boom. Such flexible booms are constructed by disposing a single strand support wire and two insulated wires into the center of a hollow outer sleeve made of lightweight material or provided as a so-called gooseneck design. The two insulated wires are coupled at one end to the microphone and at the opposite end to the transmit path amplifier. One problem with this approach, however, is that the single strand support wire tends to fracture or completely break due to work hardening caused by repeated flexing of the boom over time.
It would be desirable therefore to provide a flexible cable boom which is lightweight and comfortable for a user to wear for long periods of time and which allows placement of the microphone near the user""s mouth and which is rugged enough to avoid fracturing or breaking even after being bent repeatedly over long periods of time.
In accordance with the present invention a microphone boom includes an inner conductor having a plurality of support strands, a first insulator disposed about the inner conductor, an outer conductor disposed about the first insulator to shield the inner conductor and an outer jacket disposed about said outer conductor. With this particular arrangement a flexible microphone boom positionable to fit a plurality of different users is provided. The inner conductor is provided from a plurality of separate strands of conductive wire. By providing a support wire from a plurality of different strands of wire, the flexible cable boom may be repeatedly flexed and will not fracture. Thus, the flexible cable boom is reliable. The strands are disposed such that a first one of the strands is centrally disposed and the remaining strands are arranged about the central strand in a substantially circular pattern. The outer strands are wound about the inner strand in a spiral pattern such that the strands are maintained in a predetermined position. A microphone is coupled to a first one of the strands of the inner conductor at a first end of the boom. A second end of the boom is coupled to the housing of an ear mounted receiver or alternatively to a hanger in a so-called over-the-head headset to thus provide a head-set assembly having a flexible microphone boom.
Since the microphone boom is flexible, the microphone can be positioned proximate the user""s mouth to provide good sound and more comfort to the user. Moreover the plurality of strands of wire which provide the flexible boom of the present invention are selected having relatively small diameters and resulting in lightweight flexible microphone boom. Thus the microphone boom of the present invention aids in providing a headset which is more easily balanced on a user""s head. Moreover the manner in which the strands are disposed allows the microphone position to be maintained after adjustment.